Display device, method for controlling display, and recording medium

ABSTRACT

According to the present invention, there is provided a display device including: an operation detecting unit configured to detect a touching operation conducted on a display screen; a determination unit configured to determine whether or not the touching operation detected by the operation detecting unit includes an operation involving movement of a touch position within a predetermined region of the display screen; a display unit configured to display an image on the display screen; and a control unit configured to control to enlarge or reduce the image size on the display screen around a position of image depending on at least one of a start position and an end position on the display screen of the touching operation in the case of the determination unit has determined that the touching operation includes the operation involving movement of the touch position within the predetermined region.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is based upon and claims the benefit of priorityfrom the prior Japanese Patent Application No. 2013-195902, filed Sep.20, 2013, the entire contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a display device that performs enlargedand reduced displays by a touching operation, a method for controlling adisplay, and a recording medium.

2. Description of the Related Art

In display devices such as smartphones, screen scrolling, characterentry, etc. have been conducted by a touching operation on a screen.Further, a wrist-type display device has attracted much attention inrecent years, which a user is wearing on an arm in order to use it. Thewrist-type display device has been equipped with functions similar tothose of smartphones. The wrist-type display device is described inPatent Literature 1 (Japanese Patent Application Laid-Open PublicationNo. 2013-061176).

The wrist-type information processing terminal, however, suffers from arestriction imposed on a touching operation since the display surface ofthe wrist-type information processing terminal is smaller than thedisplay surfaces of other display devices including smartphones. Inparticular, users find it difficult to conduct operations that requirethem to use two fingers for zooming in or out on a display screen, whilethe operations can be usually conducted on smartphones as pinching-inand pinching-out, for example. The existing techniques are thusdisadvantageous in that users have to find a difficulty in conducting,with one finger, a touching operation for zooming in and out intuitivelyand simply.

BRIEF SUMMARY OF THE INVENTION

The present invention has been made in view of the above situations andan object of the present invention is thus to enable us to intuitivelyand simply conduct, with one finger, a touching operation for enlargingor reducing an image size on a screen.

According to an embodiment of the present invention, there is provided adisplay device including: an operation detecting unit configured todetect a touching operation conducted on a display screen; adetermination unit configured to determine whether or not the touchingoperation detected by the operation detecting unit includes an operationinvolving movement of a touch position within a predetermined region ofthe display screen; a display unit configured to display an image on thedisplay screen; and a control unit configured to control to enlarge orreduce the image size on the display screen displayed by the displayunit such that the image to be enlarge or reduce around a position ofimage depending on at least one of a start position and an end positionon the display screen of the touching operation in the case of thedetermination unit has determined that the touching operation includesthe operation involving movement of the touch position within thepredetermined region.

Further, according to an embodiment of the present invention, there isprovided a method for controlling the display of a display device, themethod including the steps of: detecting a touching operation conductedon a display screen; determining whether or not the touching operationdetected in the operation detecting step includes a predeterminedoperation involving movement of a touch position within a predeterminedregion of the display screen; and displaying an image on the displayscreen; and performing control to enlarge or reduce the image size onthe display screen around a position of image depending on at least oneof a start position and an end position on the display screen of thetouching operation in the case of the determination step has determinedthat the touching operation includes the operation involving movement ofthe touch position within the predetermined region.

Furthermore, there is provided a nonvolatile recording medium thatstores programs that a computer of a display device can read, in whichthe programs are for carrying out the functions of detecting a touchingoperation conducted on a display screen; determining whether or not thetouching operation detected by the operation detecting function includesa predetermined operation involving movement of a touch position withina predetermined region of the display screen; and displaying an image onthe display screen; and performing control to enlarge or reduce an imagesize on the display screen around a position of image depending on atleast one of a start position and an end position on the display screenof the touching operation in the case of the determination function hasdetermined that the touching operation includes the operation involvingmovement of the touch position within the predetermined region.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a block diagram illustrating a configuration of hardware of adisplay device according to an embodiment of the present invention;

FIG. 2 is a functional block diagram illustrating a functionalconfiguration for executing touching operation control processing of thefunctional configurations of the display device;

FIGS. 3A to 3D are schematic diagrams each illustrating a concept of anenlarged display or a reduced display on a display screen in response toan edge tracing operation.

FIG. 4 is a flow chart for describing a flow of touching operationcontrol processing executed by the display device in FIG. 1 having thefunctional configuration in FIG. 2; and

FIGS. 5A to 5D are schematic diagrams each illustrating a concept of areduced display on a display screen in response to an edge tracingoperation.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the present invention will be hereinafter describedwith reference to the drawings.

[Configuration]

FIG. 1 is a block diagram illustrating a configuration of hardware of adisplay device 1 according to an embodiment of the present invention.The display device 1 is formed as a wrist-type terminal, for example.

The display device 1 includes a central processing unit (CPU) 11, a readonly memory (ROM) 12, a random access memory (RAM) 13, a bus 14, aninput/output interface 15, an image taking unit 16, an input unit 17, anoutput unit 18, a storage unit 19, a communication unit 20, and a drive21.

The CPU 11 executes different types of processing in accordance withprograms stored in the ROM 12 or programs loaded from the storage unit19 into the RAM 13. For example, the CPU 11 executes touching operationcontrol processing in accordance with a touching operation controlprocessing program described later.

The RAM 13 adequately stores data, for example, that is necessary whenthe CPU 11 executes different types of processing.

The CPU 11, ROM 12, and RAM 13 are connected to one another via the bus14. To the bus 14, the input/output interface 15 is connected. To theinput/output interface 15, the image taking unit 16, the input unit 17,the output unit 18, the storage unit 19, the communication unit 20, andthe drive 21 are connected.

The image taking unit 16 includes an optical lens unit and an imagesensor not shown in the drawings.

The optical lens unit is formed of a condenser lens collecting lightsfor taking an image of an object, such as a focus lens or a zoom lens. Afocus lens is a lens that forms an image of an object on a lightreceiving surface of the image sensor, and a zoom lens is a lens thatfreely changes a focus distance within a limited range. The optical lensunit is additionally provided as needed with a peripheral circuit thatadjusts setting parameters including a focus point, exposure, and whitebalance.

The image sensor is formed of a photoelectric conversion element and ananalog front end (AFE), for example. The photoelectric conversionelement is, for example, a photoelectric conversion element of acomplementary metal oxide semiconductor (CMOS) type. The photoelectricconversion element receives an image of an object emitted from theoptical lens unit, and then photo-electrically converts (captures) theimage and stores an image signal for a predetermined period of time.Further, the photoelectric conversion element sequentially suppliesstored image signals to the AFE as analog signals.

The AFE executes different types of signal processing includinganalog/digital (A/D) conversion processing, on the analog image signals.Through the signal processing, digital signals are generated and areoutput as output signals of the image taking unit 16. The data indicatedby the output signals of the image taking unit 16 will be hereinafterreferred to as taken image data. The taken image data is adequatelysupplied to the CPU 11 and an image processing unit not shown in thedrawings.

The input unit 17 is formed of different types of buttons, and inputsvarious types of information in accordance with instruction operationsof a user. The output unit 18 is formed of a display or a speaker, forexample, and outputs images or sounds. The embodiment employs aconfiguration in which a touch panel as the input unit 17 is placed overa display as the output unit 18, the configuration allowing the touchingoperation on the display screen. The storage unit 19 is formed of adynamic random access memory (DRAM), for example, and stores data ofimages. The communication unit 20 controls communications with otherdevices (not shown in the drawings) via a network including theInternet.

The drive 21 is appropriately equipped with a removable media 31, whichmay be any one of a magnetic disk, an optical disk, a magneto-opticaldisk and a semiconductor memory, and so forth. The drive 21 reads aprogram from the removable media 31 and the program is installed intothe storage unit 19 if necessary. The removable media 31 can storevarious data including the data of images stored in the storage unit 19as the storage unit 19 can.

FIG. 2 is a functional block diagram illustrating a functionalconfiguration for executing touching operation control processing of thefunctional configurations of the display device 1. The touchingoperation control processing means a series of processing from detectingmovement of a touch position in a predetermined region of a displayscreen, such as the outer edges (the region extending from the outermostedges to the inner edges away from the outermost edges by a set numberof pixels) and performing an enlarged display and a reduced display onthe display screen based on the detection. The display device 1 in theembodiment not only controls a display in response to general touchingoperations including flick and tap but also performs an enlarged displayand a reduced display on the display screen by the touching operationcontrol processing. Further, the predetermined region of the displayscreen described above is not limited to the outer edges as long asenlarging or reducing an image size on the display screen is possiblebased on the detection of movement in the predetermined region of thedisplay screen.

In order for the touching operation control processing to be executed, amovement path detecting unit 51, an operation determination unit 52, anda display control unit 53 function in the CPU 11 as shown in FIG. 2.

The movement path detecting unit 51 determines whether or not thetouching operation has been performed. If having determined that thetouching operation has been performed, the movement path detecting unit51 detects a path which the touch position has followed from where thetouching operation has been started (start position) to where thetouching operation has been ended (end position). For example, themovement path detecting unit 51 sequentially detects addresses on thedisplay screen of the region from where the touching operation has beenstarted (start position) to where the touching operation has been ended(end position).

The operation determination unit 52 determines whether or not an actionof moving in the outer edges of the display screen (hereinafter referredto as edge tracing operation) has been performed, based on the movementpath taken in the touching operation detected by the movement pathdetecting unit 51. Further, if having determined that the edge tracingoperation has been performed, the operation determination unit 52detects the moving direction (from left to right or from top to bottom,for example) and the moving distance used in the edge tracing operation.

In the embodiment, the relation is previously set between the movingdirection used in the edge tracing operation and zooming-out on thedisplay screen and between the moving direction used in the edge tracingoperation and zooming-in on the display screen. Specifically, in theregions of the outer edges of the display screen which extend along theright and left sides of the display screen, a top-to-bottom movementcorresponds to zooming-out on the display screen and a bottom-to-topmovement corresponds to zooming-in on the display screen. On the otherhand, in the regions of the outer edges of the display screen whichextend along the top and bottom sides of the display screen, aleft-to-right movement corresponds to zooming-in on the display screenand a right-to-left movement corresponds to zooming-out on the displayscreen.

Further, in the embodiment, the moving distance used in the edge tracingoperation is correlated in advance with the enlargement ratio orreduction ratio for the display screen. In other words, the enlargementratio or the reduction ratio is set so that the longer the movingdistance becomes, the larger the degree of zooming in or out becomes.

If the touching operation includes the edge tracing operation, thedisplay control unit 53 enlarges or reduces an image size on the displayscreen depending on the moving direction and the moving distance for theedge tracing operation, around the start position or the end positionfor the touching operation. Further, if the direction is reversed inwhich the touch position is moved along a side of the display screen inthe edge tracing operation, the display control unit 53 switches betweenan enlarged display and a reduced display on the display screen inaccordance with the moving direction.

FIGS. 3A to 3D are schematic diagrams each illustrating a concept of anenlarged display or a reduced display of a display screen in response toan edge tracing operation. In FIG. 3A, the touch position is moved fromthe start position to a lower position on the display screen until itreaches the bottom side, and thereafter is moved in the right directionto the end position where the touching operation ends. In the example ofFIG. 3A, since the touching operation includes an edge tracing operationthat enlarges an image size, the display control unit 53 enlarges animage size on the display screen around the start position for thetouching operation with an enlargement ratio appropriate for the movingdistance for the edge tracing operation, as shown in FIG. 3B. In thatcase, since moving the touch position downward is the same as the usualdragging operation, the enlarged display around the start position isinitiated by starting the edge tracing operation after the viewing areais scrolled down on the display screen to the bottom side of the displayscreen.

On the other hand, in FIG. 3C, the touch position is moved from thestart position along the bottom side of the display screen to the left,and then is moved onto the display screen, and finally reaches the endposition, where the touching operation ends. In that case, since thetouching operation includes the edge tracing operation that reduces animage size, the display control unit 53 reduces an image size on thedisplay screen around the end position for the touching operation with areduction ratio appropriate for the moving distance for the edge tracingoperation, as shown in FIG. 3D.

[Operations]

The operations will be described next.

FIG. 4 is a flow chart for describing a flow of touching operationcontrol processing executed by the display device 1 in FIG. 1 having thefunctional configuration in FIG. 2. The touching operation controlprocessing is started when the display device 1 is turned on, and isrepeatedly performed until the display device 1 is turned off.

In Step S1, when the touching operation control processing is started,the movement path detecting unit 51 determines whether or not thetouching operation has been performed on the display screen. If thetouching operation has been performed on the display screen, Step S1makes a judgment of YES and the procedure moves on to Step S2. On theother hand, if the touching operation has not been performed on thedisplay screen, Step S1 makes a judgment of NO and the processing inStep S1 is repeated.

In Step S2, the movement path detecting unit 51 detects a path which thetouch position has followed from where the touching operation has beenstarted (start position) to where the touching operation has been ended(end position). In Step S3, the operation determination unit 52determines whether or not the edge tracing operation has been performedon the movement path for the touching operation detected by the movementpath detecting unit 51. If the edge tracing operation has beenperformed, Step S3 makes a judgment of NO and the touching operationcontrol processing is repeated. On the other hand, if the edge tracingoperation has not been performed, Step S3 makes a judgment of YES andthe procedure moves on to Step S4.

In Step S4, the operation determination unit 52 detects a movingdirection and a moving distance for the edge tracing operation. In StepS5, the display control unit 53 enlarges or reduces an image size on thedisplay screen depending on the moving direction and the moving distancefor the edge tracing operation, around the start position or the endposition for the touching operation. Specifically, the display controlunit 53 enlarges an image size on the display screen around the startposition when the edge tracing operation as shown in FIG. 3A isperformed, and reduces an image size on the display screen around theend position when the edge tracing operation as shown in FIG. 3C isperformed. After Step S5, the touching operation control processing isrepeated.

The display device 1 thus formed includes the movement path detectingunit 51, the operation determination unit 52, and the display controlunit 53.

The movement path detecting unit 51 detects the touching operationconducted on the display screen. The operation determination unit 52determines whether or not the touching operation detected by themovement path detecting unit 51 includes the edge tracing operationinvolving movement in the outer edges of the display screen. The displaycontrol unit 53 performs control so as to enlarge or reduce an imagesize on the display screen depending on the direction and the distancewith respect to the movement in the outer edges if the operationdetermination unit 52 has determined that the touching operationincludes the edge tracing operation. In this way, performing the edgetracing operation involving movement in the outer edges of the displayscreen in the process of conducting the touching operation on thedisplay screen makes is possible to enlarge or reduce an image size onthe display screen of the display device 1 in the directioncorresponding to each movement. Further, the enlargement or reduction ofan image size on the display screen is performed with an enlargementratio or a reduction ratio appropriate for the distance for the edgetracing operation. It thus becomes possible for us to conduct, with onefinger, a touching operation for zooming in and out intuitively andsimply.

Furthermore, the display control unit 53 enlarges or reduces an imagesize on the display screen, around at least one of the start positionand the end position on the display screen for the touching operation.This enables users to intuitively and simply specify the center of aregion to be zoomed in or out on the display screen.

If the direction is reversed in a process of the edge tracing operationwhere the touching position is moved in the outer edges of the displayscreen, the display control unit 53 performs control for switchingbetween an enlarged display and a reduced display on the display screenin response to the direction of the movement. This makes users to beable to check the display screen by flexibly switching between anenlarged display and a reduced display on the display screen in the edgetracing operation, whereby the convenience can be further increased ofperforming the touching operation for zooming in and out on the displayscreen.

Application Example 1

In the embodiment, when an image size on the display screen is to bereduced by the edge tracing operation, the reduced display may beperformed around either the end position or the start position for thetouching operation as shown in FIG. 3C. FIGS. 5A to 5D are schematicdiagrams each illustrating a concept of a reduced display on the displayscreen in response to the edge tracing operation. In FIG. 5A, the touchposition is moved from the start position to a lower position on thedisplay screen until it reaches the bottom side, and then is slightlymoved in the right direction. Thereafter, the touch position issignificantly moved in the reversed direction, which is the leftdirection, to the end position, where the touching operation ends.

In that case, since moving the touch position downward is the same asthe usual dragging operation, the viewing area is scrolled down on thedisplay screen, as shown in FIG. 5B. If the touch position reaches thebottom side of the display screen and then is moved to the right alongthe side, an enlarged display around the start position is initiated.Alternatively, the touch position may be moved to the left immediatelyafter it reaches the bottom side, instead of being moved to the right.Further, if the direction of moving the touch position is reversed, thatis, if the contacting position is moved to the left along the side asshown in FIG. 5C, a reduced display around the start position isinitiated. In this way, a reduced display around the start position forthe touching operation is performed as shown in FIG. 5D.

The above operational manners can achieve not only the enlarged displayshown in FIGS. 3A and 3B but also the reduced display on the displayscreen around the start position for the touching operation. Hence, anenlarged display and a reduced display can be performed in the unifiedoperational manners.

In addition to using the same operational manner for a reduced displayand for the enlarged display shown in FIGS. 3A and 3B, the end positionfor the touching operation may be used as the center of a region to bezoomed in on the display screen, as in the case of the reduced displayshown in FIGS. 3C and 3D.

In such an enlarged display, the touch position is moved from the startposition along the bottom side of the display screen to the right andthen is moved onto the display screen, and finally reaches the endposition, where the touching operation ends. Since the touchingoperation includes the edge tracing operation that enlarges an imagesize, the display control unit 53 enlarges an image size on the displayscreen around the end position for the touching operation with anenlargement ratio appropriate for the moving distance for the edgetracing operation.

The above operational manners can achieve as well not only the reduceddisplay shown in FIGS. 3C and 3D but also the enlarged display on thedisplay screen around the end position for the touching operation.Hence, an enlarged display and a reduced display can be performed in theunified operational manners.

It is to be noted the present invention is not limited to the aboveembodiment and includes variations and modifications that occur withinthe range in which the objects of the present invention can beaccomplished.

While the embodiment has been described as an example in which in theregions of the outer edges of the display screen which extend along theright and left sides of the display screen, a top-to-bottom movementcorresponds to zooming-out on the display screen and a bottom-to-topmovement corresponds to zooming-in on the display screen, the presentinvention is not limited to that example. In other words, the presentinvention may be configured so that in the regions of the outer edges ofthe display screen which extend along the right and left sides of thedisplay screen, a bottom-to-top movement corresponds to zooming-out onthe display screen and a top-to-bottom movement corresponds tozooming-in on the display screen. Likewise, while the embodiment hasbeen described as an example in which the regions of the outer edges ofthe display screen which extend along the top and bottom sides of thedisplay screen, a left-to-right movement corresponds to zooming-in onthe display screen and a right-to-left movement corresponds tozooming-out on the display screen, the present invention is not limitedto that example. In other words, the present invention may be configuredso that in the regions of the outer edges of the display screen whichextend along the top and bottom sides of the display screen, aright-to-left movement corresponds to zooming-in on the display screenand a left-to-right movement corresponds to zooming-out on the displayscreen. Moreover, in the outer edges of the display screen, the relationcan be reversed between the direction of movement along the left andright sides and the enlargement/reduction of an image size, or betweenthe direction of movement along the top and bottom sides and theenlargement/reduction of an image size. For example, moving the touchposition in the outer edges of the display screen in a counterclockwisedirection corresponds to zooming-in on the display screen and moving thetouch position in a clockwise direction corresponds to zooming-out onthe display screen.

Further, while a wrist-type terminal is used in the embodiment as thedisplay device 1 according to the present invention, it is not the onlyexample of the display device 1. For example, the present invention isapplicable to notebook-sized personal computers, tablet terminals,printers, television receivers, video cameras, mobile navigationdevices, mobile phones, smartphones, portable game machines, and soforth.

The series of processing described above can be executed by eitherhardware or software. In other words, the functional configuration inFIG. 2 is only exemplary. It is sufficient if the display device 1 isequipped with functions that can practically execute the series ofprocessing and any other functional block than that in FIG. 2 may beused for realizing the functions. Further, a single function block maybe formed of hardware only, software only, or a combination of hardwareand software.

If the series of processing is to be executed by software, the programsof the software are installed from a network or a recording medium intoa computer, for example. The computer may be a computer build indedicated hardware, or be a computer such as a general personal computerthat is capable of executing different functions with different programsinstalled therein.

The recording medium having the programs includes not only the removablemedia 31 in FIG. 1 distributed separately from the device body to a userfor providing the user with programs but also a recording medium builtin the device body in advance and provided to the user. The examples ofthe removable media 31 include a magnetic disk (floppy disk, forexample), an optical disk, and a magneto-optical disk. The examples ofthe optical disk include a compact disk-read only memory (CD-ROM), adigital versatile disk (DVD), and a Blu-ray Disc (registered trademark).The magneto-optical disk is an MD (Mini-Disk), for example. Further, therecording medium built in the device body in advance and provided to theuser is the ROM 12 in FIG. 1 storing programs or hardware contained inthe storage unit 19 in FIG. 1, for example.

In the specification, the steps of describing the programs stored in therecording medium include not only processing performed in accordancewith the order of the steps but also processing performed in parallelwith one another or individually performed.

While several embodiments of the present invention have been described,the embodiments are only exemplary and do not limit the technical rangeof the present invention. It should be understood that the presentinvention may be implemented in other different embodiments and variouskinds of alterations including omissions and replacements may occur aslong as they are within the gist of the present invention. Theembodiments and modified examples are within the scope and gist of theinvention described in the specification, etc., and within the scope ofthe invention described in the appended claims or the equivalentsthereof.

What is claimed is:
 1. A display device comprising: an operationdetecting unit configured to detect a touching operation conducted on adisplay screen; a determination unit configured to determine whether ornot the touching operation detected by the operation detecting unitincludes an operation involving movement of a touch position within apredetermined region of the display screen, the predetermined regionhaving a height and a width; a display unit configured to display animage on the display screen; and a control unit configured to control toenlarge or reduce the image size on the display screen displayed by thedisplay unit such that the image is enlarged or reduced in the case ofthe determination unit has determined that the touching operationincludes the operation involving movement of the touch position withinthe predetermined region.
 2. The display device according to claim 1,wherein the control unit is configured to enlarge or reduce the imagesize on the display screen along a direction in which the touch positionis moved.
 3. The display device according to claim 1, wherein thecontrol unit is configured to perform control for switching between anenlarged display and a reduced display on the display screen in responseto reversal of movement direction of the touch position if thedetermination unit has determined that the direction of moving the touchposition has been reversed in a process where it is moved within thepredetermined region on the display screen.
 4. The display deviceaccording to claim 1, wherein the control unit controls an enlargementratio or a reduction ratio used for enlarging or reducing an image sizeon the display screen depending on a distance for which the touchposition has been moved within the predetermined region, if thedetermination unit has determined that the touching operation includesan operation involving movement of the touch position within thepredetermined region of the display screen.
 5. The display deviceaccording to claim 1, wherein the touching operation is a singletouching operation.
 6. The display device according to claim 1, whereinthe predetermined region is outer edges of the display screen.
 7. Adisplay device comprising: an operation detecting unit configured todetect a touching operation conducted on a display screen; adetermination unit configured to determine whether or not the touchingoperation detected by the operation detecting unit includes an operationinvolving movement of a touch position within a predetermined region ofthe display screen, the predetermined region extending along at leastone side of the display screen; a display unit configured to display animage on the display screen; and a control unit configured to control toenlarge or reduce the image size on the display screen displayed by thedisplay unit such that the image is enlarged or reduced in the case ofthe determination unit has determined that the touching operationincludes the operation involving movement of the touch position withinthe predetermined region.
 8. The display device according to claim 7,wherein the control unit is configured to enlarge or reduce the imagesize on the display screen along a direction in which the touch positionis moved.
 9. The display device according to claim 7, wherein thecontrol unit is configured to perform control for switching between anenlarged display and a reduced display on the display screen in responseto reversal of movement direction of the touch position if thedetermination unit has determined that the direction of moving the touchposition has been reversed in a process where it is moved within thepredetermined region on the display screen.
 10. The display deviceaccording to claim 7, wherein the control unit controls enlargementratio or a reduction ratio used for enlarging or reducing an image sizeon the display screen depending on a distance for which the touchposition has been moved within the predetermined region, if thedetermination unit has determined that the touching operation includesan operation involving movement of the touch position within thepredetermined region of the display screen.
 11. The display deviceaccording to claim 7, wherein the touching operation is a singletouching operation.
 12. The display device according to claim 7, whereinthe predetermined region comprises outer edges of the display screen.13. A method, comprising: detecting, by system comprising a processor, atouching operation conducted on a display screen; determining, by thesystem, whether or not the touching operation includes an operationinvolving movement of a touch position within a predetermined region ofthe display screen, the predetermined region having a height and awidth; displaying, by the system, an image on the display screen; andcontrolling, by the system, to enlarge or reduce the image size on thedisplay screen such that the image is enlarged or reduced in the case ofdetermining that the touching operation includes the operation involvingmovement of the touch position within the predetermined region.
 14. Amethod, comprising: detecting, by a system comprising a processor, atouching operation conducted on a display screen; determining, by thesystem, whether or not the touching operation includes an operationinvolving movement of a touch position within a predetermined region ofthe display screen, the predetermined region extending along at leastone side of the display screen; displaying, by the system, an image onthe display screen; and controlling, by the system, to enlarge or reducethe image size on the display screen such that the image is enlarged orreduced in the case of determining that the touching operation includesthe operation involving movement of the touch position within thepredetermined region.
 15. A non-transitory recording medium that storesprograms that a computer of a display device can read, wherein theprograms are for carrying out the functions of: detecting, a touchingoperation conducted on a display screen; determining whether or not thetouching operation includes an operation involving movement of a touchposition within a predetermined region of the display screen, thepredetermined region having a height and a width; displaying an image onthe display screen; and controlling to enlarge or reduce the image sizeon the display screen such that the image is enlarged or reduced in thecase of determining that the touching operation includes the operationinvolving movement of the touch position within the predeterminedregion.
 16. A non-transitory recording medium that stores programs thata computer of a display device can read, wherein the programs are forcarrying out the functions of: detecting a touching operation conductedon a display screen; determining whether or not the touching operationincludes an operation involving movement of a touch position within apredetermined region of the display screen, the predetermined regionextending along at least one side of the display screen; displaying animage on the display screen; and controlling to enlarge or reduce theimage size on the display screen such that the image is enlarged orreduced in the case of determining that the touching operation includesthe operation involving movement of the touch position within thepredetermined region.